text: #    Licensed under the Apache License, Version 2.0 (the "License"); you may
  #    not use this file except in compliance with the License. You may obtain
  #    a copy of the License at
  #
  #         http://www.apache.org/licenses/LICENSE-2.0
  #
  #    Unless required by applicable law or agreed to in writing, software
  #    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
  #    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
  #    License for the specific language governing permissions and limitations
  #    under the License.
  
  from neutron_lib.db import model_base
  import sqlalchemy as sa
  from sqlalchemy import orm
  
  from neutron.db import models_v2
  
  
  class PortSecurityBinding(model_base.BASEV2):
      port_id = sa.Column(sa.String(36),
                          sa.ForeignKey('ports.id', ondelete="CASCADE"),
                          primary_key=True)
      port_security_enabled = sa.Column(sa.Boolean(), nullable=False)
  
      # Add a relationship to the Port model in order to be to able to
      # instruct SQLAlchemy to eagerly load port security binding
      port = orm.relationship(
          models_v2.Port,
          backref=orm.backref("port_security", uselist=False,
                              cascade='delete', lazy='joined'))
      revises_on_change = ('port',)
  
  
  class NetworkSecurityBinding(model_base.BASEV2):
      network_id = sa.Column(sa.String(36),
                             sa.ForeignKey('networks.id', ondelete="CASCADE"),
                             primary_key=True)
      port_security_enabled = sa.Column(sa.Boolean(), nullable=False)
  
      # Add a relationship to the Port model in order to be able to instruct
      # SQLAlchemy to eagerly load default port security setting for ports
      # on this network
      network = orm.relationship(
          models_v2.Network,
          backref=orm.backref("port_security", uselist=False,
                              cascade='delete', lazy='joined'))
      revises_on_change = ('network',)
  